Device for controlling motors.



PATENTED SEPT. 26, 1905.

F. B. DUNCAN. DEVICE FOR CONTROLLING MOTORS.

APPLICATION FILED DBO. 30, 1901 2 SHEETS-SHEET 1 r I I l l I I WW4 wiw 72218 flityif.

PATENTED SEPT. 26, 1905.

F. B. DUNCAN.

DEVICE FOR CONTROLLING MOTORS.

APPLICATION FILED D30. 30, 1901 2 SHEETS-SHEET 2.

, v IN- UNITED STATES PATENT oEEIoE.

FREDERICK B. DUNCAN, OF MADISON, IVISCON SIN, ASSIGNOR TO NORTHERN ELECTRICAL MANUFACTURING COMPANY, OF MADISON, IVISCON SIN, A CORPORATION OF IVISCONSIN.

DEVICE FOR CONTROLLING MOTORS.

No. 800,611. Specification of Letters Patent. Patented Sept. 26, 1905.

Application filed December 30, 1.901. Serial No. 37,656.

To all whom it y 007mg? the solenoid the engaging part will be out of Be itknown that I, FREDERIOK B. DUNoAN,a engagement with the teeth. The solenoid D subject of the King of Great Britain, residing is connected by conductor D with the conat Madison, in the county of Dane and State of tact D of the reversingswitch E and also with 5 I/Visconsin, have invented a certain new and the switch or push-button A by conductor D usefulImprovementin DevicesforOontrolling Said push-button is connected to the negative Motors, of which the following is a speciiicaline of the system by conductor X. A holdtion. ing-magnet F is associated with the arm C,

My invention relates to devices for controland its armature is provided with an engag- IO ling motors, and has for its object to provide ing piece F, which engages said teeth when .5 a new and improved device and system of this the magnet is energized, there being a redescription. tracting-spring F which pulls the armature My invention 1s illustrated in the accomaway from the magnet when it is demagnetpanymg drawings, wherein ized, so as to release the arm. The engag- 5 Figure 1 is a diagrammatic view of a sysing piece F is connected by a flexible link 7 tem embodying my invention. Fig. 2 is a with the core of the solenoid or magnet G, diagrammatic view showing the connections adapted when actuated to permit the arm of and associated parts of one motor and controlthe controller to move, so as to slow down the ling mechanism. Fig. 3 is a view showing the motor. The magnet F is connected with the 20 reversing-switch. arm C by conductor F and with the positive Like letters refer to like parts throughout line by eonductorF. A short-errcurting conthe several figures. ductor F" passes around said magnet and In Fig. 1 I have illustrated a series of dethrough the push-button A, so that when said vices or machines involving a system embod ypush-button is closed the magnet will be short- 5 ing my invention. For purposes of illustracircuited. The core of the solenoid G is protion I have taken a machine-shop containing vided with an engaging arm G, pivoted therelathes, planers, and the like. Each machine to and also pivoted at G This arm engages A is operated by a separate motor, the rheothe teeth C when the solenoid is energized, stats or controllers T for which are located on and the retracting-spring G withdraws it 3 a switchboard B at some convenient part of from engagement when the solenoid is deen- 5 the shop and out of reach of the operator of ergized. This solenoid Cr is connected to the the lathe or other machine. The controllers conductor D and hence the positive line of are operated by means of push-buttons A A the system, by conductor Cr and with the A A*, &c., located on the lathes, there being push-button A" by conductor G Said push- 55 suitable connections between the push-buttons button is connected by conductor X with the 9 and motor and the controller on the switchnegative line of the system. board. The reversing-switch E is provided with two In Fig. 2 I have illustrated one motor and sets of arms E and E", which engage suitable the controlling mechanism therefor. In this contacts. This switch is adapted to be worked 4 construction the usual armature resistance is automatically and is provided with a toothed provided, said resistance being controlled by disk E, which is engaged by a hook E carthe arm C. This arm moves over suitable conried by a part pivotally connected to the core tacts connected with the armature resistance of the reversing solenoid or magnet I. \Vhen R and the field resistance R and is provided this magnet is energized, thereversing-switch 45 with the retracting-spring C. Said arm is is moved so as to reverse the currents in the I00 also provided with a ratchet segment or rack motor. Said solenoid is connected to the posihaving teeth O adapted to be engaged by the tive line by conductor L and to the push-butpawl or engaging part D on the core of the ton A by conductor 1, said push-button bemagnet or solenoid D. This engaging part ing connected to the negative line by con- 5 is attached to a piece which is pivotally conductor X. 5

nected to the core of said magnet so that it The positive line of the system is connected may have a slight side movement, and said by conductor K with the contact K, (see Fig. piece is also provided with the inclined pro- 8,) and the armature of the motor is connectjection D which engages a suitable pin or ed by conductors L with the contacts L and 55 stop,sothatwhennocurrentisflowingthrough L of the switch. The negative line is con- I10 nected to contact L of the switch, and the field-circuit M of the motor is connected to the.

The use and operation of my invention are as follows: When it is desired to start the motor, the pusl1button A is pressed. This completes the circuit through solenoid D, said circuit being traced as follows: from positive line Y to switch E, thence by conductor D through solenoid 1 thence by conductor D to push-button A, thence to conductorX, and thence back to the negative line. Solenoid D is then energized, lifting its core and moving the arm one notch. The arm is held in this position by the engaging piece F on the armature of the magnet F, the circuit through said magnet being as follows: from positive line Y through switch E, conductor D, arm C, conductor F magnet F, and conductor F thence through the field-magnet coils of the motor. thence back to contact M of the switch, and thence to the negative line Z. To move the arm up another notch, the push-button is released,permitting the core to fall and is then again pressed, the operation hereinbefore set out being repeated. The movement of the arm cuts out the armature resistance R, so as to speed up the motor, and near the end of itsmovement cuts resistance R into the fieldcircuit, thus further increasing the speed of the motor. It will thus be seen that the arm 0 may be held in any desired position, depending upon the number of times the pushbutton is pushed. 1f now itis desired to stop the motor, the push-button A is pushed. This short-circuits the magnet F, the circuit instead of going through said magnet passing through conductor F through the push-button, and back to the field-coil M, the rest of the circuit being the same as before. When the magnet F is short-circuited. it becomes demagnetized, and the spring F moves the ar mature so that the engaging piece F is withdrawn from the teeth, and the arm C is released, the spring then throwing said arm suddenly back to its initial or off position. The flexiblelink between the engaging piece F and the core of solenoid G bends at the pivoted. point and permits this movement of the engaging piece F. If it is desired to slow down the motor gradually when it is going at any particular speed, the push-button A is pushed. This completes the circuit through solenoid G, said circuit being as follows: from positive line Y through switch E, conductor D conductor G'flmagnet G and conductor Githrough push-button A and thence through conductor X and back to the negative line. The solenoid G is now energized and draws its core inwardly. The engaging pieceF is then moved out of engagement with the teeth C, and the bent arm G is thrust forward so as to engage said teeth. This lets the spring of arm pull said arm back one tooth. If new the push-button is released, the parts take the position shown in Fig. 2, and if it is desired to move the arm baclnvard farther the pushbutton is again pushed. It will thus be seen that the arm may be moved backward, so to throw any desired resistance in the armature-circuit and slow down the motor to the desired speed. This is of the greatest importance in connection with such machines as lathes, for it is often necessary to slow down the speed when the work is in the lathe. If it is necessary to stop the motor to slow down the speed, a mark is left on the work by the tool. All this is avoided by means of my controlling device. The circuit through the armature is as follows: from positive line Y to contact K of switch E, thence across said switch to contact I)", (see Fig. 3,) thence by conductor 1) to arm 0, thence through armature resistance, thence to contact S, (see Fig. 3,) thence to contact L, thence through the armature, thence to contact L, thence to contact L", and back to the negative line Z. If it is desired to reverse the motor, the pushbutton A is pushed. This completes the circuit through solenoid I, said circuit being as follows: from positive line Y through conductor I to solenoid I, thence by conductor 1 to push-button A, and thence through conductor X back to the negative line. The solenoid l is thus energized and moves its core upwardly so as to rotate the switch a quarter of a turn, thus changing the arms which make contact with the contacts and reversing the current. The movement of this switch has no effect upon the operation of the other devices of the controller.

It will thus be seen that l have here a device for controlling the various machines in a shop at the machine, the controlling parts being located away from the machine so as to be out of the reach of the operator, and that the motor is started up or slowed down by a step-by-step process entirely independent of the operator and beyond his control, and that there is no way by which the machine can be started up or. slowed down without going through this step-by-step process, thus preventing injury to the motor by the sudden change of resistance in the armature-circuit.

I clairn 1. The combination with a motor of a eontrolling-rheostat, a device for moving the rheostat by a step-by-step movement to cut out resistance, a holding device for holding the rheostat-arm, a releasing device for releasing the rheostat-arm by a step-by-step movement, so that it may be returned to its IIO initial position, and a connection between the movable parts associated with the holdingmagnet and the releasing-magnet.

2. The combination with a device to be driven of a motor associated therewith, a rheostat at a distant point adapted to be connected in circuit with said motor, acontrolling mechanism for the arm thereof, adapted to move said arm by a step-by-step movement in both directions, and push-buttons or switches at the machine for controlling the operation of said controlling mechanism.

3. The combination with a machine to be driven of an electric motor, a rheostat at a distant point, a step-by-step actuating-solenoid associated with the arm of said rheostat, and provided with a core adapted to be connected with and disconnected from the arm of the rheostat, a holding device associated with the rheostat-arm and adapted to engage it at a different point from that of the controlling rheostat-arm and a switch at the machine for controlling said solenoid, whereby resistance is cut out from the armature-circuit by a stepby-step process.

4t. The combination with a machine to be driven of an electric motor, a rheostat at a distant point, a step-by-step actuating-solenoid associated with the arm of said rheostat, a switch at the machine for controlling said solenoid, a holding-magnet associated with said rheostat-arm and adapted to hold it in the position to which it is moved by the stepby-step actuating device, the actuating-solenoid and holding-magnet adapted to engage and disengage with the rheostat-arm successively during the operation of the device and a push-button at the machine for rendering said holding-magnet inoperative.

5. The combination with a machine to be driven of an electric motor, a rheostat or starting-box at a distant point, a step-by-step actuating-solenoid associated with the arm of said rheostat, a switch at the machine for controlling said solenoid, a holding-magnet associated with said rheostat-arm and adapted to hold it in the position to which it is moved by the step-by-step actuating device, a push-button at the machine for rendering said holdingmagnet inoperative, a releasing-magnet associated with said arm and provided with attachments which release the arm by a step-by-step movement, and a controlling connection between the parts controlled by the releasingmagnet and the holding-magnet and a switch at the machine for controlling said releasingmagnet.

6. The combination with a machine to be driven of an electric motor, a rheostat or starting-boX at a distant point, a step-by-step actuating-solenoid associated with the arm of said rheostat, a switch at the machine for con trolling said solenoid, a holding-magnet associated with said rheostat-arm and adapted to hold it in the position to which it is moved by the step-by-step actuating device, a push-button at the machine for rendering said holdingmagnet inoperative, a releasing-magnet associated with said arm and provided with attachments which release the arm by a step-by-step movement, a switch at the machine for controlling said releasing-magnet, a reversingswitch for said motor at a distance from the machine, and a switch at the machine for automatically controlling it.

7. The combination with a lathe of an electric motor,a rheostat or starting-box therefor, having a contact-arm provided with a rack, a solenoid located near said rack, provided with a core having a pawl or ratchet adapted to engage the teeth of the rack so as to move said arm a predetermined amount each time the solenoid is energized, a holding-magnet associated with said rack and having an engaging device on its armature for holding the arm in the position to which it is moved, suitable switches or push-buttons on the lathe for con trolling said magnet and solenoid, whereby a step-by-step movement of the starting-box arm is insured when the motor is being started.

8. The combination with a lathe of an electric motor, a starting-box therefor out of the reach of the lathe operator, a rack on the contact-arm of said starting-box, a solenoid located near said rack and provided with a core having a pawl adapted to engage said rack, a push-button or switch on the lathe in position to be conveniently controlled by the operator, whereby the starting-box arm is moved by a step-by-step motion when the push-button or switch is operated and a stop device adapted to engage the rack on the contact-arm when it is released by the ratchet associated with the said solenoid.

FREDERICK B. DUNCAN.

Vitnesses:

ALBERT B. DEAN, AUG. J. BUENZLI. 

